Does tuberculosis threaten our ageing populations?

A retrospective study of tuberculosis prevalence amongst patients attending a tertiary hospital in Riyadh, Saudi Arabia

Tuberculosis (TB) is a public health challenge that affects all genders and age groups and is a single leading infectious disease killer globally. We retrospectively investigated the prevalence of TB and anti-TB drug resistance among patients treated at the Prince Sultan Military Medical City (PSMMC) between the years 2000 and 2017. Patient demographic variables and drug susceptibility test results were obtained from TB notification records located in the TB laboratory at PSMMC. A total of 58,141 records were reviewed of which 1123 (2%) specimens were positive for Mycobacterium tuberculosis. Of the positive, 621 (55%) were from pulmonary specimens. Males over the age of 15 years accounted for 60% of the positive specimens. Drug resistance to at least one drug was detected in 90 (8%) of which 60 (5.3%), 24 (2%) 6 (0.5%) patients were mono-drug-resistant, poly-drug resistant and multidrug resistant (MDR-TB) respectively. Resistance to isoniazid and streptomycin were the most frequently found among first-line tuberculosis drugs, accounting for 4.5% and 3.8% of drug resistance cases respectively. Our findings show low prevalence of tuberculosis and multidrug resistant TB among patients treated at PSMMC over a 17-year period. Nationwide assessment is needed to get a clear picture of the TB burden across Saudi Arabia and inform national policies for eradication of TB.

Impact of Age on Outcome of Rifapentine-Based Weekly Therapy for Latent Tuberculosis Infection

BACKGROUND

Weekly rifapentine and isoniazid (3HP) is gaining popularity for latent tuberculosis infection treatment because of its short course and high completion rate. Prior to widespread use, comprehensive 3HP treatment assessment covering an all-age population is essential.

METHODS

Participants receiving ≥1 3HP dose from September 2014 to December 2019 were stratified into elderly (≥65 years), middle-aged (>35 & <65 years), and younger (≤35 years) age groups. This study investigated the impact of age on treatment outcome, particularly systemic drug reactions (SDRs) and 3HP discontinuation.

RESULTS

Overall, 134 of 579 (23.1%) participants were elderly. The completion rate was 83.1% overall and was highest and lowest in the younger group (94.5%) and elderly (73.9%) group, respectively. However, the 3HP discontinuation rate was not significantly different among the 3 groups in multivariate logistic regression analysis. In total, 362 (62.5%) participants experienced 1 or more adverse drug reactions (ADRs), of which 38 (10.5%) and 98 (27.1%) required temporary and permanent treatment interruption, respectively. The SDR risk was 11.2% in overall and 17.1% in the middle-aged group, 3.04-fold higher than that in the elderly group (P = .025). This finding was consistently observed in different clinical settings. Hypertensive events accompanied with flu-like symptoms occurred in 11.2% of elderly participants, and accounted for 50% of grade ≥3 ADRs.

CONCLUSIONS

With proper medical support and programmatic follow-up, the 3HP completion rate is >70% even in elderly participants. In middle-aged and elderly individuals, 3HP should be employed with caution because of risk of SDRs and hypertensive events, respectively. Summary: Under programmatic medical support, widespread use of weekly rifapentine and isoniazid (3HP) for latent tuberculosis treatment is possible for its high completion rate. 3HP should be employed with caution for risk of systemic drug reactions and hypertensive events in middle-aged and elderly individuals, respectively.

Epidemiology of Tuberculosis in Multi-Host Wildlife Systems: Implications for Black (Diceros bicornis) and White (Ceratotherium simum) Rhinoceros

Cases of tuberculosis (TB) resulting from infection with Mycobacterium tuberculosis complex (MTBC) have been recorded in captive white (Ceratotherium simum) and black (Diceros bicornis) rhinoceros. More recently, cases have been documented in free-ranging populations of both species in bovine tuberculosis (bTB) endemic areas of South Africa. There is limited information on risk factors and transmission patterns for MTBC infections in African rhinoceros, however, extrapolation from literature on MTBC infections in other species and multi-host systems provides a foundation for understanding TB epidemiology in rhinoceros species. Current diagnostic tests include blood-based immunoassays but distinguishing between subclinical and active infections remains challenging due to the lack of diagnostic techniques. In other species, demographic risk factors for MTBC infection include sex and age, where males and adults are generally at higher risk than females and younger individuals. Limited available historical information reflects similar age- and sex-associated patterns for TB in captive black and white rhinoceros, with more reports of MTBC-associated disease in black rhinoceros than in white rhinoceros. The degree of MTBC exposure in susceptible wildlife depends on their level of interaction, either directly with other infected individuals or indirectly through MTBC contaminated environments, which is dependent on the presence and abundance of infected reservoir hosts and the amount of MTBC shed in their excreta. Captive African rhinoceros have shown evidence of MTBC shedding, and although infection levels are low in free-ranging rhinoceros, there is a risk for intraspecies transmission. Free-ranging rhinoceros in bTB endemic areas may be exposed to MTBC from other infected host species, such as the African buffalo (Syncerus caffer) and greater kudu (Tragelaphus strepsiceros), through shared environmental niches, and resource co-utilization. This review describes current knowledge and information gaps regarding the epidemiology of TB in African rhinoceros.

Expanding the role of bacterial vaccines into life-course vaccination strategies and prevention of antimicrobial-resistant infections

A crisis in bacterial infections looms as ageing populations, increasing rates of bacteraemia and healthcare-associated infections converge with increasing antimicrobial resistance and a paucity of new antimicrobial classes. New initiatives are needed to develop bacterial vaccines for older adults in whom immune senescence plays a critical role. Novel vaccines require an expanded repertoire to prevent mucosal diseases such as pneumonia, skin and soft tissue infections and urinary tract infections that are major causes of morbidity and mortality in the elderly, and key drivers of antimicrobial resistance. This review considers the challenges inherent to the prevention of bacterial diseases, particularly mucosal infections caused by major priority bacterial pathogens against which current vaccines are sub-optimal. It has become clear that prevention of many lung, urinary tract and skin infections requires more than circulating antibodies. Induction of Th1/Th17 cellular responses with tissue-resident memory (Trm) cells homing to mucosal tissues may be a pre-requisite for success.

Impact of adjuvant therapeutic surgery on the health-related quality of life of pulmonary tuberculosis patients

This study aimed to determine the health-related quality of life (HRQoL) of patients with pulmonary tuberculosis (TB) and to assess its change after a therapeutic surgical procedure. In this scenario, the purpose was to elucidate and quantify the effect of various demographic, epidemiological, clinical, surgical and psychosocial details on this variable.

A prospective cohort of 40 patients undergoing therapeutic surgery for pulmonary TB (Study of Human Tuberculosis Lesions (SH-TBL) cohort) was recruited in Tbilisi, Georgia, between 2016 and 2018. HRQoL was assessed by administering the St George's Respiratory Questionnaire (SGRQ) and a novel psychosocial questionnaire, the BCN-Q, both at baseline and at 6 months post-surgery.

A statistically and clinically significant improvement in the SGRQ total score was observed at follow-up, although it did not reach the values found for the healthy population. The differences between time points were statistically significant for the following groups: women, age <40 years, body mass index ≥20 kg·m⁻², nonsmokers, drug-susceptible and drug-resistant participants, both new and relapsed patients, early culture negativisation, cases with a single lesion, either lesions <35 mm or ≥35 mm, and lesion, lobe and lung resections.

The analysis of BCN-Q together with the SGRQ showed that several of its items, such as marital status, living conditions, nutrition, employment, external support, certain attitudes towards the healthcare system, emotional burden and sleep troubles, can impact HRQoL.

These results highlight the benefit of adjuvant therapeutic surgery for pulmonary TB in selected patients in terms of HRQoL and suggest that a comprehensive approach including demographic, epidemiological, clinical and psychosocial variables may more accurately predict TB evolution and prognosis.

Adjuvant therapeutic surgery in selected pulmonary TB patients improves their health-related quality of life. Impact of psychosocial variables on HRQoL may be assessed using a newly developed questionnaire, namely BCN-Q.https://bit.ly/2A169rR

Advantages and Challenges of Tailored Regimens for Drug-Resistant Tuberculosis: A StopTB Italia Look into the Future

The emerge of drug-resistant tuberculosis (TB) strain in recent decades is hampering the efforts of the international community to eliminate the disease worldwide. The World Health Organization (WHO) has drafted many strategies to achieve this ambitious goal. In the very beginning, the aim was to standardize inadequate regimens used in many countries and, thereafter, evolved to tackle the social determinants which hinder TB elimination. However, following the path of narrowing the clinical vision to deal with TB, there is an increased need to personalize the treatment considering both patients and pathogen unique characteristics. In our narrative review, we report the advantages and the backwards in developing a method to implement the concept of precision medicine to the treatment of TB. In this dissertation, we highlight the importance to address different aspects of the diseases encompassing the host and pathogen features, as well as the needs to further implement an adequate follow-up based on the available resources. Nevertheless, many things may hamper the vision of precision medicine in TB, such as the complexity and the costs to develop novel compounds and the costs related to global-scale implementation of patient-centered follow-up. To achieve the ambitious goal of TB elimination, a radical change in TB treatment is needed in order to give a more comprehensive approach based both on patients’ peculiarities and driven by drug susceptibility tests and whole-genome sequencing.

Active Pulmonary Tuberculosis in Elderly Patients: A 2016-2019 Retrospective Analysis from an Italian Referral Hospital

Tuberculosis (TB) in the elderly (>65 years old) has increasingly become a global health problem. It has long been recognized that older people are vulnerable to developing tuberculosis. We retrospectively evaluated data from patients older than 65 years diagnosed with pulmonary TB admitted to the National Institute for Infectious Diseases L. Spallanzani, Rome, Italy, from 1 January 2016 to 31 December 2019. One hundred and six consecutive patients were diagnosed with pulmonary TB and 68% reported at least one comorbidity and 44% at least one of the TB risk-factors. Out of the 26 elderly patients who reported an adverse event, having risk factors for TB (O.R. (Odds Ratios) = 1.45; 95% CI 1.12-3.65) and the presence of cavities on Chest X-rays (O.R. = 1.42; 95% CI 1.08-2.73) resulted in being more likely to be associated with adverse events in elderly patients. Having weight loss (O.R. = 1.31; 95% CI 1.08-1.55) and dyspnea (O.R. = 1.23; 95% CI 1.13-1.41) resulted in being significant predictors of unsuccessful treatment outcome in elderly patients. Older people with TB represent a vulnerable group, with high mortality rate, with a challenging diagnosis. Hospitalizations in tertiary referral hospital with clinical expertise in TB management can be useful to improve the outcome of these fragile patients.

Extraspinal articular tuberculosis: An 11-year retrospective study of demographic features and clinical outcomes in East London

OBJECTIVES

To describe demographic features, clinical outcomes and diagnostic delay amongst patients with extra-spinal articular tuberculosis (TB) in a low-incidence setting.

METHODS

Cases of TB treated at our institution between 2004 and 2014 were identified via the London TB register (LTBR). Demographic features of extra-spinal articular TB cases were compared to controls with TB at all other sites. For articular cases (excluding individuals <16 years or with spinal TB without peripheral joint involvement) clinical data were retrospectively collected.

RESULTS

6,146 TB patients were identified over the study period; 146 (2.4%) cases had extra-spinal articular infection. There was no difference in median age between extra-spinal articular TB cases and controls with TB at other sites (31 vs 32 years, p = 0.57). Articular cases were more likely to be male (70.6% vs 59.5%, p = 0.007), Bangladeshi (28.7% vs 18.0%) or Pakistani (24.0% vs 16.1%) and were less likely to be Black-African (9.5% vs 19.8%) (p < 0.001). 93 cases were included in the case series; 85 (88.5%) were migrants and 83 (89.2%) were South Asian. Knee and elbow joints were affected in 22 (23.7%) and 18 (19.4%) cases respectively. The median durations of pre-healthcare and healthcare associated delay were 16 and 6 weeks respectively. Where mycobacterial culture was performed, 57/75 (76%) were positive for Mycobacterium tuberculosis. 86 (92.5%) cases received standard quadruple therapy for a median of 6 months (IQR 6-9). Recurrence of TB infection occurred in 4 (4.3%) cases and there were no TB related deaths. Seven (7.6%) cases required surgical intervention.

CONCLUSIONS

Extra-spinal articular TB more commonly affected men and people of South Asian ethnicity. Significant diagnostic delays were identified, including avoidable healthcare-associated delays.

Old age-associated enrichment of peripheral T regulatory cells and altered redox status in pulmonary tuberculosis patients

Aging influences the susceptibility and prognosis to various infectious diseases including tuberculosis (TB). Despite the impairment of T-cell function and immunity in older individuals, the mechanism for the higher incidence of TB in the elderly remains largely unknown. Here, we evaluated the age-associated immune alterations, particularly in effector and Treg responses in pulmonary TB patients. We also evaluated the impact of redox status and its modulation with N-acetyl-cysteine (NAC) in elderly TB. Higher frequency of Treg cells and reduced IFN-γ positive T cells were observed among older TB patients. The elevated number of Treg cells correlated tightly with bacillary load (i.e. disease severity); which declined significantly in response to successful anti-tubercular treatment. We could rescue Myobacterium tuberculosis-specific effector T cell (Th1) responses through various in vitro approaches, for example, Treg cell depletion and co-culture experiments, blocking experiments using antibodies against IL-10, TGF-β, and programmed death-1 (PD-1) as well as NAC supplementation. We report old age-associated enrichment of Treg cells and suppression of M. tuberculosis-specific effector T (Th1) cell immune responses. Monitoring these immune imbalances in older patients may assist in immune potentiation through selectively targeting Treg cells and/or optimizing redox status by NAC supplementation.

Engagement of private healthcare providers for case finding of tuberculosis and diabetes mellitus in Pakistan

BACKGROUND

The rising co-epidemic of tuberculosis (TB) and diabetes mellitus (DM) is a challenge for constrained health systems in low and middle-income countries. Diabetes is a known risk factor for tuberculosis and associated with poor tuberculosis treatment outcomes, while tuberculosis is associated with worsening glycemic control. We investigated the performance of bi-directional TB and DM case finding approaches through a private-sector engagement model in Karachi, Pakistan.

METHODS

Between July 2016 and July 2018, private health care providers were engaged to generate referrals for bi-directional TB and DM screening at private diagnostic and treatment centers in Karachi, Pakistan. Individuals diagnosed with TB underwent glycated hemoglobin (HbA1c) testing at the time of anti-tuberculous treatment initiation and at three -month follow up stage. All individuals with a history of diabetes or random blood sugar of greater than 200 mg/dl were screened for TB using a chest X-ray and Xpert MTB/RIF.

RESULTS

A total of 6312 persons with tuberculosis were tested on HbA1c at treatment initiation, of whom 1516 (24%) were newly diagnosed with DM. About one third of those with HbA1c in the diabetic range (≥ 6.5%) at baseline were found to have a normal HbA1c (< 5.7%) result at 3-month follow-up. A total of 3824 individuals with DM, of whom 2396 (63%) were known cases and 1428 (37%) were newly identified with random blood sugar > 200 mg/dl, underwent chest x-ray and Xpert MTB/RIF testing, with 321 (13.4%) known and 54 (3.8%) new diabetics respectively identified with tuberculosis.

CONCLUSION

This study demonstrates a high yield of TB and DM through bidirectional screening and the feasibility of engagement of private sector in finding missing cases of tuberculosis and diabetes. Given the high prevalence of undiagnosed DM in individuals with TB tuberculosis patients, there is a need to scale-up DM screening within TB programmes. Increased awareness of the high risk of TB among individuals with DM is needed among private health providers and screening for TB among diabetics should be strongly considered.

New Concepts in Tuberculosis Host Defense

Tuberculosis (TB) host defense depends on cellular immunity, including macrophages and adaptively acquired CD4⁺ and CD8⁺ T cells. More recently, roles for new immune components, including neutrophils, innate T cells, and B cells, have been defined, and the understanding of the function of macrophages and adaptively acquired T cells has been advanced. Moreover, the understanding of TB immunology elucidates TB infection and disease as a spectrum. Finally, determinates of TB host defense, such as age and comorbidities, affect clinical expression of TB disease. Herein, the authors comprehensively review TB immunology with an emphasis on new advances.

Bayesian reconstruction of Mycobacterium tuberculosis transmission networks in a high incidence area over two decades in Malawi reveals associated risk factors and genomic variants

Understanding host and pathogen factors that influence tuberculosis (TB) transmission can inform strategies to eliminate the spread of Mycobacterium tuberculosis (Mtb). Determining transmission links between cases of TB is complicated by a long and variable latency period and undiagnosed cases, although methods are improving through the application of probabilistic modelling and whole-genome sequence analysis. Using a large dataset of 1857 whole-genome sequences and comprehensive metadata from Karonga District, Malawi, over 19 years, we reconstructed Mtb transmission networks using a two-step Bayesian approach that identified likely infector and recipient cases, whilst robustly allowing for incomplete case sampling. We investigated demographic and pathogen genomic variation associated with transmission and clustering in our networks. We found that whilst there was a significant decrease in the proportion of infectors over time, we found higher transmissibility and large transmission clusters for lineage 2 (Beijing) strains. By performing evolutionary convergence testing (phyC) and genome-wide association analysis (GWAS) on transmitting versus non-transmitting cases, we identified six loci, PPE54, accD2, PE_PGRS62, rplI, Rv3751 and Rv2077c, that were associated with transmission. This study provides a framework for reconstructing large-scale Mtb transmission networks. We have highlighted potential host and pathogen characteristics that were linked to increased transmission in a high-burden setting and identified genomic variants that, with validation, could inform further studies into transmissibility and TB eradication.

Explaining age disparities in tuberculosis burden in Taiwan: a modelling study

Background

Tuberculosis (TB) burden shows wide disparities across ages in Taiwan. In 2016, the age-specific notification rate in those older than 65 years old was about 100 times as much as in those younger than 15 years old (185.0 vs 1.6 per 100,000 population). Similar patterns are observed in other intermediate TB burden settings. However, driving mechanisms for such age disparities are not clear and may have importance for TB control efforts.

Methods

We hypothesised three mechanisms for the age disparity in TB burden: (i) older age groups bear a higher risk of TB progression due to immune senescence, (ii) elderly cases acquired TB infection during a past period of high transmission, which has since rapidly declined and thus contributes to little recent infections, and (iii) assortative mixing by age allows elders to maintain a higher risk of TB infection, while limiting spillover transmission to younger age groups. We developed a series of dynamic compartmental models to incorporate these mechanisms, individually and in combination. The models were calibrated to the TB notification rates in Taiwan over 1997–2016 and evaluated by goodness-of-fit to the age disparities and the temporal trend in the TB burden, as well as the deviance information criterion (DIC). According to the model performance, we compared contributions of the hypothesised mechanisms.

Results

The ‘full’ model including all the three hypothesised mechanisms best captured the age disparities and temporal trend of the TB notification rates. However, dropping individual mechanisms from the full model in turn, we found that excluding the mechanism of assortative mixing yielded the least change in goodness-of-fit. In terms of their influence on the TB dynamics, the major contribution of the ‘immune senescence’ and ‘assortative mixing’ mechanisms was to create disparate burden among age groups, while the ‘declining transmission’ mechanism served to capture the temporal trend of notification rates.

Conclusions

In settings such as Taiwan, the current TB burden in the elderly may be impacted more by prevention of active disease following latent infection, than by case-finding for blocking transmission. Further studies on these mechanisms are needed to disentangle their impacts on the TB epidemic and develop corresponding control strategies.

Review of Evidence for Using Chest X-Rays for Active Tuberculosis Screening in Long-Term Care in Canada

Background: People living in long-term care facilities (LTCF) are at high risk to develop active tuberculosis primarily as a result of reactivation of a latent TB infection, or endemic transmission between residents. Current national guidelines in Canada are to use a posterior-anterior and lateral chest X-ray to screen for TB for those over 65 years old, upon admission to a LTCF.

Objective: To assess the available evidence for cost benefits of universal chest X-ray screening for new LTCF residents.

Methodology: We conducted a search for all articles published until September 2018, in PubMed and WorlCat databases, in English, using a combination of key words: chest X-ray, chest radiography or CXR, long-term care, elderly, screening, and tuberculosis. We also reviewed publicly available guidelines for screening new residents to LTCF from across Canada. We report on a qualitative synthesis of the evidence in the documents retrieved.

Results: The final review yielded four cost-effectiveness studies (2 of 4 conducted in countries with low incidence), one systematic review, one recommendation/editorial, and one cohort study. We found that in a tuberculosis low-incidence country the CXR cost per identified case was $672,298 CAD. Enacting a more targeted screening program, perhaps one that tests only those who previously had TB, or other high-risk medical conditions may enhance the cost-effectiveness.

Recommendations: We suggest reviewing the screening policy for active TB in people entering LTCF, which is based on a CXR. The results indicate that a targeted search for active TB in people with symptoms or other high-risk medical conditions may be more cost-effective.

[Low detection rate and therapeutic success of tuberculosis in a prison in EcuadorBaixo recrutamento de pacientes e sucesso no tratamento da tuberculose em uma prisão do Equador]

Objetivo.

Evaluar el control de la tuberculosis pulmonar en un centro de privación de la libertad e identificar los factores de riesgo asociados con tratamiento no exitoso en la cárcel más grande en Ecuador.

Métodos.

Se analizaron los datos de vigilancia de la prisión y de una cohorte de internos diagnosticados con tuberculosis (TB) entre los años 2015 y 2016. Se excluyeron los registros sin desenlace en el tratamiento. Se estimó el porcentaje de sintomáticos respiratorios (SR) identificados y la tasa de incidencia de TB. Los factores asociados con el tratamiento no exitoso se estimaron con regresión logística binomial.

Resultados.

De 59 846 consultas médicas, 3% se identificó como SR y, de estos, 326 reclusos tenían TB, 184 fueron analizados. La tasa de incidencia de TB en la prisión fue de 3 947/100 000 habitantes. El porcentaje de tratamiento exitoso fue de 70,4% (65,6% curado y 4,8% con tratamiento completo) y 29,4% de tratamiento no exitoso (12,5% de pérdidas durante el seguimiento, 5% fallecieron, 1,1% de fracasos de tratamiento y 10,8% no fueron evaluados). La seropositividad para el virus de la inmunodeficiencia humana (VIH) se asoció con un mayor riesgo de tratamiento no exitoso (riesgo relativo: 1,66, intervalo de confianza de 95%: 1,33-2,07).

Conclusión.

La incidencia de TB en la prisión es 123 veces más alta que en la población general de Ecuador. Los prisioneros coinfectados con TB-VIH tienen mayor riesgo de no tener un tratamiento exitoso y se requiere articulación entre los ministerios de salud y de justicia que permita la implementación adecuada de protocolos de salud y de la estrategia Fin a la TB.

Risk factors of tuberculosis infection among health care workers: A meta-analysis

BACKGROUNDS

Health care workers (HCWs) are globally known to have high risk of tuberculosis (TB) infection while risk factors of TB infections among HCWs are still inconclusive.

OBJECTIVES

To perform a meta-analysis in effort to identify risk factors of TB infection among HCWs.

METHODS

A meta-analysis was conducted between February and July 2019. Papers were searched in Pubmed, Embase, Cochrane, and Web of science and information of interest were extracted. The correlation and effect estimation were analyzed using random or fixed effect model.

RESULTS

A total of 12 studies consisting of 2871 cases and 15,673 controls were included and six risk factors were available for meta-analysis. Cumulative calculation found that age, working duration, and types of job were significant risk factor of TB infection while gender, active TB contact, and types of workplace were not associated significantly with TB infection among HCWs. Our pooled data revealed that decreased risk of TB infection was observed in age less than 30 years (age < 30 years vs. age ≥ 30 years) and working duration less than five years (working duration < 5 years vs. ≥5 years). Being more than 40 years, working more than 10 years, and being physicians increased the risk of TB infection significantly compared to age ≤40 years, working duration ≤10 years, and other job types, respectively.

CONCLUSIONS

Our meta-analysis has identified the significant risk factors of TB infection among HCWs. Our results may be useful for establishing future TB prevention program among HCWs.

Time to diagnosis of tuberculosis is greater in older patients: a retrospective cohort review

Introduction

Age-related immunosenescence influences the presentation of tuberculosis (TB) in older patients. Here, we explore the clinical and radiological presentation of TB in the elderly and the factors associated with time to treatment for TB.

Methods

This is a retrospective cohort study comparing the clinical, radiological and demographic characteristics of TB patients aged ≥65 years with TB patients aged 18–64 years in a large cohort of TB patients in the UK. Factors associated with the time to presentation and time to treatment were identified using a multivariable analysis model.

Results

1023 patients were included in the analyses: 679 patients aged 18–64 years and 344 patients aged ≥65 years. “Classical” symptoms of TB (cough, haemoptysis, fever, nights sweats and weight loss) were less common among older patients with pulmonary TB (PTB) (p<0.05), but dyspnoea was more common among older patients (p=0.001). Time from presenting in secondary care to starting treatment was shorter in younger compared with older patients: 3 versus 15 days (p=0.001). When adjusted for age, factors associated with shorter time to treatment from symptom onset include sex (male versus female) (hazard ratio (HR) 1.23 (95% CI 1.05–1.46)), UK born (HR 1.23 (95% CI 1.05–1.46)) and HIV (HR 2.07 (95% CI 1.30–3.29)). Only age remained an independent predictor of time to treatment in a multivariable model (HR 0.98 (95% CI 0.98–0.99)). For those with PTB, chest radiography findings showed that cavitation and lymphadenopathy were more common among younger patients (p=0.001).

Conclusions

Older patients aged ≥65 years with TB had fewer “classical” clinical and radiological presentations of TB, which may explain longer times to starting treatment from symptom onset compared with younger patients aged <65 years.

A retrospective UK study in patients with TB shows only age remains an independent predictor of time to treatment in a multivariable model. Older patients have fewer of the “classical” clinical and radiological features of TB compared with younger patients.http://bit.ly/2yHc0OL

Ambulatory independence is associated with higher incidence of latent tuberculosis infection in long-term care facilities in Taiwan

BACKGROUND/PURPOSE

Tuberculosis (TB) in the elderly population remains a major challenge in areas with intermediate disease burden like Taiwan. Despite the increasing burden and high risks of TB in the elderly population, particularly those living in long-term care facilities (LTCFs), diagnostic testing for latent tuberculosis infection (LTBI) has not been carefully evaluated in this group. This study aimed to investigate the prevalence and predictors of LTBI in older adults living in LTCFs.

METHODS

Older adults living in seven LTCFs in Taiwan were prospectively enrolled between January and July 2017. Interferon-gamma release assay (IGRA) through QuantiFERON-TB Gold In-tube was used to determine presence of LTBI. Predictors for LTBI were analyzed.

RESULTS

A total of 258 participants were enrolled, including 240 older residents (mean age, 81.6 years; male, 51.2%) and 18 employees (mean age, 64.8 years; male, 22.2%). The proportion of independent status in ambulation assessments significantly declined with aging (p < 0.001). The IGRA-positivity rate in LTCFs was 31.4% (81/258), which consisted of 73 (30.4%) residents and 8 (44.4%) employees. The IGRA results were different with respect to the ambulation status (p = 0.052). In the multivariate logistic regression analysis, the only independent predictor of LTBI among older adults in LTCFs was independent ambulation (odds ratio, 2.16; 95% confidence interval, 1.09-4.28; p = 0.027).

CONCLUSIONS

There was a high prevalence of LTBI among older adults in LTCFs in Taiwan. Independent ambulation was the only independent predictor of LTBI.

Completion rate of latent tuberculosis infection treatment in patients aged 65 years and older

INTRODUCTION

There are insufficient data on the treatment of latent tuberculosis infection (LTBI) in elderly patients. We investigated the completion rate of treatment in elderly LTBI patients.

METHODS

A retrospective multicentre study was conducted at five university hospitals in South Korea. We reviewed the electronic medical records of patients aged 65 years and older who were diagnosed with LTBI via positive interferon-gamma release assay results between January 2016 and December 2018. Treatment completion was defined as ingestion of more than 80% of all prescribed medications without loss to follow-up.

RESULTS

During the study period, 127 LTBI patients aged 65 years and older visited outpatient department. Among them, 77 patients aged 65-78 years (median age, 69 years [interquartile range, 66-71 years]) who received LTBI treatment were analysed. Common reasons for IGRA testing in elderly patients were health-care worker (n = 33, 42.9%) and household contact with infectious TB patients (n = 18, 23.4%). The overall completion rate of LTBI treatment was 83.1% (n = 64), and the completion rate of 3-month isoniazid plus rifampin regimen was 88.4%. Adverse effects were reported in 23 patients (29.9%), and an increase in aminotransferase level was the most common adverse effect (n = 11, 14.3%). Three patients (3.9%) with the adverse effect discontinued treatment and 10 (13.0%) patients were lost to follow-up.

CONCLUSIONS

LTBI treatment in patients aged 65-78 years was relatively well tolerated. In LTBI treatment in elderly patients, the majority of discontinuation of treatment was due to loss to follow-up rather than adverse effects of anti-TB medications.

Epidemiology and disease burden of tuberculosis in south of Tunisia over a 22-year period: Current trends and future projections

BACKGROUND

Tuberculosis (TB) is a public health problem worldwide. Characterizing its trends over time is a useful tool for decision-makers to assess the efficiency of TB control programs. We aimed to give an update on the current chronological trends of TB in Southern Tunisia from 1995 to 2016 and to estimate future trajectories of TB epidemic by 2030.

METHODS

We retrospectively collected data of all notified TB new cases by the Center of Tuberculosis Control between 1995 and 2016 in South of Tunisia. Joinpoint Regression Analysis was performed to analyze chronological trends and annual percentage changes (APC) were estimated.

RESULTS

In the past 22 years, a total of 2771 cases of TB were notified in Southern Tunisia. The annual incidence rate of TB was 13.91/100,000 population/year. There was a rise in all forms of TB incidence (APC = 1.63) and in extrapulmonary tuberculosis (EPTB) (APC = 2.04). The incidence of TB increased in children and adult females between 1995 and 2016 (APC = 4.48 and 2.37, respectively). The annual number of TB declined in urban districts between 2004 and 2016 (APC = -2.85). Lymph node TB cases increased (APC = 4.58), while annual number of urogenital TB decreased between 1995 and 2016 (APC = -3.38). Projected incidence rates would increase to 18.13 and 11.8/100,000 population in 2030 for global TB and EPTB, respectively.

CONCLUSIONS

Our study highlighted a rise in all forms of TB and among high-risk groups, notably children, females and lymph node TB patients in the last two decades and up to the next one.

Demographic risk factors for extra-pulmonary tuberculosis among adolescents and adults in Saudi Arabia

Despite low infectious potential of extrapulmonary tuberculosis (EPTB), it poses significant clinical challenges in terms of diagnosis and treatment monitoring. Understanding the main demographical risk factors for disease characteristics of EPTB plays a crucial role in speeding up diagnosis process and improving overall clinical experience. The aim of this study was to investigate the main demographical and clinical risk factors for EPTB among adults and adolescents for the first time in Saudi Arabia. A cross-sectional multicenter study was carried out on a collection of 902 extrapulmonary Mycobacterium tuberculosis complex (MTBC) isolates with demographical and clinical data. All isolates were subjected to spoligotyping and 24-loci based MIRU-VNTR typing. The association between two potential variables was assessed using odd ratios (OR) calculations. Independent risk factors for EPTB and diseases characteristics of EPTB were identified using multivariate regression model analyses. Gender was found to be significantly associated with lymph node, gastrointestinal, central nervous system and urogenital TB. Lymph node TB showed statistical association to age group below 25 years, non-Saudis and South East Asian ethnicity. While gastrointestinal TB demonstrated an association with patients above 60 years old, and Saudis. Multivariate analysis showed that gender is an independent risk factor to urogenital TB (p 0.03) and lymph node TB (p 0.005). On the other hands, South Asian (p 0.01) and South East Asian (p 0.03) ethnicities were both identified as independent risk factors significantly associated with EPTB. MTBC lineages, site of infections, gender, HIV and smear positivity showed no significant association. Nationwide qualitative-studies are highly warranted in the future to further understand the main demographic risk factors for disease characteristics of EPTB.

Altered monocyte phenotypes but not impaired peripheral T cell immunity may explain susceptibility of the elderly to develop tuberculosis

Tuberculosis (TB) is the leading killer due to a single infectious disease worldwide. With the aging of the global population, the case rate and deaths due to TB are highest in the elderly population. While general immunosenescence associated with old age is thought to contribute to the susceptibility of the elderly to develop active TB disease, very few studies of immune function in elderly individuals with Mycobacterium tuberculosis (M.tb) infection or disease have been performed. In particular, impaired adaptive T cell immunity to M.tb is one proposed mechanism for the elderly's increased susceptibility primarily on the basis of the decreased delayed type hypersensitivity response to tuberculin-purified protein derivative in the skin of elderly individuals. To investigate immunological reasons why the elderly are susceptible to develop active TB disease, we performed a cross-sectional observational study over a five year period (2012-2016) enrolling participants from 2 age groups (adults: 25-44 years; elderly: 65 and older) and 3 M.tb infection statuses (active TB, latent TB infection, and healthy controls without history of M.tb infection). We hypothesized that impaired peripheral T cell immunity plays a role in the biological susceptibility of the elderly to TB. Contrary to our hypothesis, we observed no evidence of impaired M.tb specific T cell frequency or altered production of cytokines implicated in M.tb control (IFN-γ, IL-10) in peripheral blood in the elderly. Instead, we observed alterations in monocyte proportion and phenotype with age and M.tb infection that suggest their potential role in the susceptibility of the elderly to develop active TB. Our results suggest a potential link between the known widespread low-grade systemic inflammation of old age, termed "inflammaging," with the elderly's specific susceptibility to developing active TB. Moreover, our results highlight the need for further research into the biological reasons why the elderly are more susceptible to disease and death from TB, so that public health systems can be better equipped to face the present and future problem of TB in an aging global population.

Potential effect of household environment on prevalence of tuberculosis in India: evidence from the recent round of a cross-sectional survey

Background

Tuberculosis (TB) has been a major health problem globally since ages, and even today, it is a major cause of morbidity in millions of people each year. In 2015 alone, TB accounted for about 1.4 million deaths globally, with India carrying the biggest burden of the disease. The physical environment of the household, an individual living in, has a significant influence on the incidence of TB. Thus, an understanding of the socio-economic, demographic and environmental factors that individuals are exposed to is of importance. The objective of present study is to examine the association of household environment with the prevalence of Tuberculosis in India.

Methods

The study utilizes data from the fourth round of National Family Health Survey (NFHS-4), 2015-16, which was collected from self-reported information pertaining to Tuberculosis in the household questionnaire. The specific question was, “Does any usual resident of your household suffer from tuberculosis?” the response to which helped in the detection of Tuberculosis. Binary Logistic regression was performed from which appropriate inferences are drawn on the association of household environment with Tuberculosis.

Results

Prevalence of TB was found to be the highest among elderly people (0.9%), no education (0.4%) and people belonging to the poorest wealth quintile (0.53%). Family members who were regularly (daily) exposed to smoke (second-hand smoke) inside the house were more prone to getting tuberculosis (OR = 1.49; CI = 1.39-1.61) as compared with households where people do not smoke inside the house. Further, households having a finished wall (OR = 0.7; CI = 0.6-0.8) are less likely to get TB than the households with mud walls. Households that shared their toilets with other households are more likely to get hold of Tuberculosis (OR = 1.2; CI = 1.1-1.4).

Conclusions

Results strongly suggest that a contaminated household environment increases the risk of tuberculosis in India. There are multiple risk factors that are strongly associated with Tuberculosis: smoke inside house, type of cooking fuel, separate kitchen, floor, roofing and wall material, number of persons sleeping in a room, sharing toilet and potable water with other households; and individual characteristics such as age, sex, educational attainment, marital status, place of residence and wealth index.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0627-3) contains supplementary material, which is available to authorized users.

Data-driven model for the assessment of Mycobacterium tuberculosis transmission in evolving demographic structures

In the case of tuberculosis (TB), the capabilities of epidemic models to produce quantitatively robust forecasts are limited by multiple hindrances. Among these, understanding the complex relationship between disease epidemiology and populations' age structure has been highlighted as one of the most relevant. TB dynamics depends on age in multiple ways, some of which are traditionally simplified in the literature. That is the case of the heterogeneities in contact intensity among different age strata that are common to all airborne diseases, but still typically neglected in the TB case. Furthermore, while demographic structures of many countries are rapidly aging, demographic dynamics are pervasively ignored when modeling TB spreading. In this work, we present a TB transmission model that incorporates country-specific demographic prospects and empirical contact data around a data-driven description of TB dynamics. Using our model, we find that the inclusion of demographic dynamics is followed by an increase in the burden levels predicted for the next decades in the areas of the world that are most hit by the disease today. Similarly, we show that considering realistic patterns of contacts among individuals in different age strata reshapes the transmission patterns reproduced by the models, a result with potential implications for the design of age-focused epidemiological interventions.

Epidemiological, clinical and mechanistic perspectives of tuberculosis in older people

With the ageing population globally, tuberculosis (TB) in older people becomes a major clinical and public health challenge. In many Asian countries, especially those located in the eastern and southeastern parts of the continent, geriatric TB is a significant problem. TB in the older patients is more difficult to diagnose in the early course of disease, and has poorer treatment outcomes, largely as increased failure and death. More drug-induced adverse reactions are also experienced by this population during TB therapy. Oxidative stress and mitochondrial dysfunction are now well recognized to be associated with the ageing process, and it is likely that the cellular and molecular perturbations interact inextricably with the immunological dysfunction biophysiologically inherent to ageing. These underlying mechanistic bases putatively contribute to the development of TB in the geriatric population and worsen the disease outcomes, especially when the TB is compounded by co-morbid conditions such as smoking and diabetes mellitus. Unravelling these mechanisms further would yield knowledge that might potentially help to prevent reactivated TB in older people, and also to better manage the established disease with drug regimens and other new therapeutic strategies. In addition, addressing the social elements associated with geriatric TB is also imperative in the relief of individual patient suffering and improvement of overall disease control.

Socioeconomic status and biomedical risk factors in migrants and native tuberculosis patients in Italy

Action on social determinants is a main component of the World Health Organization End Tuberculosis (TB) Strategy. The aim of the study was to collect information on socioeconomic characteristics and biomedical risk factors in migrant TB patients in Italy and compare it with data collected among Italian TB patients. A cross-sectional study was conducted among TB patients aged ≥18 years over a 12-months enrolment period in 12 major Italian hospitals. Information on education, employment, housing and income was collected, and European Union Statistics on Income and Living Conditions index was used to assess material deprivation. Among migrants, we also analyzed factors associated with severe material deprivation. Migrants were compared with younger (18-64 years) and older (65+ years) Italians patients. Out of 755 patients enrolled (with a median age of 42 years, interquartile range: 31-53), 65% were migrants. Pulmonary, microbiologically confirmed, and new cases were 80%, 73%, and 87% respectively. Prevalence of co-morbidities (i.e. diabetes, chronic kidney disease, neoplastic diseases and use of immunosuppressive drugs) was lower among migrants compared to Italian TB patients, while indicators of socioeconomic status, income and housing conditions were worst in migrants. Forty-six percent of migrants were severely deprived vs. 9% of Italians (p<0.0001, 11.3% and 5.5% among younger and older Italians, respectively). Among migrants, being male, older, irregular, unemployed, with a shorter time spent in Italy, a lower education level, and without a co-morbidity diagnosis were factors associated with severe material deprivation at multi-variable logistic regression. Moreover, socioeconomic indicators for Italian patients did not differ from those reported for the general Italian population, while migrant TB patients seem to have a higher prevalence of severe material deprivation than other migrants residing in Italy. Intervention to address the needs of this population are urgent.

Treatment delay and fatal outcomes of pulmonary tuberculosis in advanced age: a retrospective nationwide cohort study

BACKGROUND AND OBJECTIVE

Studies focusing on pulmonary tuberculosis in advanced age (≥80 years) are lacking. This study aimed to explore treatment delay, outcomes and their predictors in this group.

METHODS

Adult (≥20 years) patients with pulmonary tuberculosis were identified from the National Health Insurance Research Database of Taiwan from 2004 to 2009. Treatment completion and mortality rates were noted at one year after treatment.

RESULTS

Among the 81,081 patients with pulmonary tuberculosis identified, 13,923 (17.2%) were aged ≥80 years, and 26,897 (33.2%) were aged 65-79 years. The treatment completion, mortality rates and treatment delay were 54.8%, 34.7% and 61 (12-128) [median, (1st-3rd quartiles)] days in patients aged ≥80 years, 68.3%, 18.5% and 53 (8-122) days in patients aged 65-79 years, and 78.9%, 6.5% and 21 (1-84) days in patients aged <65 years, respectively. The elder patients were more likely to receive second-line anti-tuberculosis agents. The treatment completion rate decreased with older age, female sex, comorbidities, low income, requiring second-line anti-tuberculosis agents, severity of pulmonary tuberculosis and longer treatment delay. Older age, female sex, comorbidities, low income, and not undergoing rapid molecular diagnostic tests were independently associated with longer treatment delays.

CONCLUSIONS

Pulmonary tuberculosis in advanced age has a longer treatment delay and a higher mortality rate. Applying rapid molecular diagnostic tools may reduce treatment delay and should be integrated into the diagnostic algorithm for pulmonary tuberculosis, particularly in elderly patients.

Using genotyping to delineate tuberculosis transmission in long-term care facilities: single facility 4-year experience

Background

Residents in long-term care facilities (LTCFs) are vulnerable to tuberculosis (TB) transmission; however, to delineate possible routes of TB transmission in LTCFs is difficult. This study aimed to address the use of regular genotyping surveillance to delineate TB transmission in LTCFs.

Methods

All of Mycobacterium tuberculosis isolates in the reported 620-bed LTCF between July 2011 and August 2015 were genotyped, and we retrospectively compared epidemiological data and genotyping results.

Results

A total of 42 subjects were diagnosed with culture-positive pulmonary TB infection during the 4-year period. Their median age was 76.5 years, and 64.3% (27/42) of them were male. Genotyping identified 5 clustered TB infections involving 76.2% (32/42) of all TB subjects. In a multivariate logistic regression model adjusted for age, sex, chronic obstructive pulmonary disease, and body mass index, subjects with clustered TB infection were less likely to be Activities of Daily Living (ADL)-dependence (adjOR 0.073, 95% CI 0.007–0.758) when compared with subjects having individual TB infections. Prolonged surveillance is essential given that the median interval to diagnose secondary subjects was 673 days. Finally, only 63.0% (17/27) of the 27 secondary TB subjects in this study had contact history with index subject in the same ward.

Conclusions

In conclusion, possible routes of TB transmission in a complex TB outbreak at LTCFs might be delineated by routine genotyping surveillance and regular health check-up.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2526-2) contains supplementary material, which is available to authorized users.

Determinants of mortality in elderly patients with tuberculosis: a population-based follow-up study

Elderly individuals with tuberculosis (TB) are more likely to have a non-specific clinical presentation of TB and high mortality. However, factors associated with mortality in elderly TB patients have not been extensively studied. This retrospective cohort study aimed to identify factors associated with death among elderly Taiwanese with TB. All elderly patients with TB from 2006 to 2014 in Taipei, Taiwan, were included in a study. Multiple logistic regression was used to identify the factors associated with death in elderly TB patients. The mean age of the 5011 patients was 79·7 years; 74·1% were men; 32·7% had mortality during the study follow-up period. After controlling for potential confounders, age ⩾75 years (reference: 65-74 years), male sex, end-stage renal disease (ESRD), malignancy, acid-fast bacilli-smear positivity, TB-culture positivity, pleural effusion on chest radiograph and notification by an ordinary ward or intensive care unit were associated with a higher risk of all-cause death; while high school, and university or higher education, cavity on chest radiograph and directly observed therapy were associated with a lower risk of all-cause death. This study found that the proportion of death among elderly patients with TB in Taipei, Taiwan, was high. To improve TB treatment outcomes, future control programmes should particularly target individuals with comorbidities (e.g. ESRD and malignancy) and those with a lower socio-economic status (e.g. not educated).